The present invention relates to improvements to motorized vehicles and finds particular application on those types of vehicles, such as electric wheelchairs, employed by the handicapped to provide added mobility.
It will be appreciated that although the description of the invention that follows hereinafter is made with reference to electrified wheelchairs, the invention finds application on all manner of motorized carts such as may be found in the workplace, on the golf course, and so on.
Motorized wheelchairs of the same general configuration as described and illustrated herein are known. Such wheelchairs, however, possess a number of disadvantages in their construction and operation which pose substantial difficulties for thier users. Some units can be disassembled only to a limited extent, such as by removing the chair portion from the motorized platform. The platform, comprising the unit's suspension, batteries, motors and drive train, is usually far too heavy and bulky to be wielded by the actual user, requiring that an attendant be on hand to assist in loading the wheelchair into an automobile for transport or to remove it up a flight of stairs, for instance. Other units can be broken down into a greater number of parts although the disassembly procedure requires that the operator bend at the knees and perform a number of operations requiring a high degree of manual dexterity. Again, such actions are often beyond the capabilities of the user. It will be appreciated that similar difficulties are encoutered when the wheelchair is to be reassembled.
Other disadvantages encountered with known motorized wheelchairs occur with respect to difficult-to-operate seat clamping and braking mechanisms.
Further, because these vehicles by their very nature possess a relatively high centre of gravity, grades and inclines beyond a predetermined threshold cannot be traversed with safety. The attempted solution to this problem on known vehicles has been to provide add-on items including additional axles and wheels to widen the stance or track of the wheelchair. Such add-on apparatus has proven awkward and cumbersome to install and use, requiring the use of special tools such as retaining ring pliers and once again necessitating a degree of physical dexterity often not possessed by the handicapped user. The attempted solutions have moreover been deficient in not providing a means to concurrently lengthen the wheelbase of the chair.